Researchers Examine Location Tracking in Mobile Apps: ShmooCon

Some mobile applications are making real-life games of hide-and-go-seek a whole lot easier, according to research presented recently at the ShmooCon 2015 security conference.

On Jan. 17, Synack researchers Colby Moore and Patrick Wardle presented research demonstrating how users' locations can be tracked in real-time. The researchers examined several popular applications, including the Tinder and Grindr dating apps. Tinder was previously vulnerable to multiple vulnerabilities - and is still vulnerable but with much less accuracy - while Grindr is still vulnerable to very accurate geolocation, Wardle explained to SecurityWeek after the conference.

"There were a number of bugs that in combination cause these vulnerabilities to be very serious," he said, such as APIs that are vulnerable to location spoofing and a lack of authentication.

Other bugs included not rate limiting requests to APIs, which allowed the researchers to harvest large amounts of information quickly, and logic to hide or show data being implemented at the UI level so that sensitive information was still transmitted unbeknownst to the user.

"Many apps, especially Grindr, are sharing location information at the maximum precision possible," he said. "The values being shared indicated precision down to the sub-meter level. It’s hard to draw the line between vulnerability and logic flaws or poor implementation. I could consider all some piece of both. Bottom line, little thought was given to the implementation of location services and security in Grindr and many other apps."

The researchers passed the information along to Grindr last year, which responded to the issue amidst reports that authorities in Egypt were using the app to target gay men.

In the case of Grindr, the server-side APIs were open to anybody, Wardle said.

"You could say, "give me all nearby users" and it would, down to scary level of accuracy," he said. "You can move your location and ask again – twice - and then perform a trilateration attack to pinpoint the exact absolute location of any user…For other apps, such as Angry Birds… it was reported that governments were sniffing insecurely transmitted geolocation data to track users. In this scenario, you’d need some sort of view of the network traffic. In either case, no malware, or access to the user’s device is needed."

"Bottom line, he said, "any app that shares location data with other users will be vulnerable to some degree."

The researchers recommend that users assume that if an app is using their location they are vulnerable to tracking and should disable location sharing at the OS-level if they are concerned. In addition, they recommend developers implement secure communications correctly via SSL, refrain from using more geo-location precision than is necessary, require authentication and implement proper rate limiting logic on the backend.